Recently, in the field of pathology, etc., there are known virtual microscopes which can be operated as if an operator observes a sample through a real microscope in a virtual space of a personal computer or the like. Sample data to be handled in such a virtual microscope is based on image data of a sample acquired in advance by using a real microscope at high resolution.
For realizing image operation in the virtual microscope, it is demanded that an image acquisition apparatus which acquires image data (virtual slides) of a sample to be thus used in a virtual microscope acquires an image of a sample at sufficiently high resolution. For such image acquisition with high resolution, for example, a method for acquiring an observation image for a whole sample by imaging while scanning the sample two-dimensionally by an image pickup device has been used (for example, refer to Patent Documents 1 and 2). Thus, acquiring an image while scanning a sample two-dimensionally makes it easy to acquire a high-resolution image of the whole sample in a short time.